Hydraulic transmission for motor vehicles



Aug. 19, 1930. w. E. LAPE HYDRAULIC TRANSMISSION FOR MOTOR VEHICLES Filed June l0l 1924 3 Sheets-Sheet 1 )hr Ess Aug. 19, 1930. w, E. LAPE HYDRAULIC TRANSMISSION FOR MOTOR VEHICLES 3 Sheets-Sheet 2 Filed June l0..l 1924 fr Ess Aug. 19, 1930. w. E. LAPE 1373,58',

HYDRAULIC TRANSMISSION FOR MOTOR VEHICLES Filed June 10. 1924 3 Sheets-Sheet 3 Patented Aug. 19, 1930 PATENT @FFECE WILLARD E. LAPE, OF SYRACUSE, NEW YORK HYDRAULIC TRANSMISSION FOR MOTOR VEHICLES Application filed June 10, 1924. Serial No. 719,092.

This invention relates to a hydraulic transmission mechanism for motor driven vehicles and more particularly in connection with those having internal combustion engines as the motive power.

The main object is to transmit rotary motion from the engine shaft to the traction wheels by means of a liquid such for example, as lubricating oil of low viscosity in order that it may serve the additional purpose as a lubricant for the various operating parts.

Another object is to provide simple and efficient means under the control of the operator for starting, stopping, changing the speed and reversing the direction of rotation of the traction wheels through the medium of a single control lever operated from the drivers position.

A further object is to enable the speed to be changed from zero to maximum in either direction throughV negligible or widely'variable gradations in which thetorque varies inversely as the speed and is therefore, greatest `when starting or at slowest possible speeds so that the speed may be varied directly as the amount and velocity of the oil is circulated through the conducting system.

A still further object is to control this circulation through the medium of a pump actuated by the engine and to provide means for varying the stroke of the pistons of the pump from a neutral or no stroke position to the maximum stroke provided for so that when the pistons are adjusted to the neutral position, no circulation will take place and will positively prevent movement of the car in either direction thereby reducing the liability of theft and affording simple and convenient means for controlling the speed and momentum of the vehicle. Y

Other objects and uses relating to specific parts of the transmission mechanism will be brought out in the following description.

In the drawings Figure l is a top plan of a chassis of a motor vehicle having an internal combustion engine as the motive power and showing the compact relation of the hydraulic mechanism for transmitting power from the engine shaft to the traction wheels.

Figure 2 is an enlarged vertical sectional View taken on line 2 2, Figure 1.

Figure 3 is a sectional view taken in the planes of line 3 3, Figure 2, except that the by-pass pipe connecting the lower and upper sides of the pump case is shown in elevation.

Figure 4 is an enlarged longitudinal sectional view of one of the rotor cases and the liquid-impelled rotors therein showing also the adjacent end of one of the rear axle sections upon which they are mounted.

Figure 5 is an enlarged transverse Vertical sectional view taken on line 5 5, Figure l looking forwardly, except that portions oi the liquid conduits are broken away, showing mainly the pump case and pump pistons therein and one of the rotor cases and rotors therein.

Figure 6 is a sectional view taken in the plane of line 6 6, Figure 5, and Figure 7 70 is an enlarged sectional View of a portion of the by-pass conduit shown in Figure 3, and the valve mechanism for controlling the passage of fluid through the by-pass.

lThe chassis of the vehicle may be of any suitable construction consisting, in this instance, of opposite frame bars 1 mounted upon front and rear supporting wheels 2- and 3- and carrying at its front end, a motor such as an internal combustion engine 5- having a suitable drive shaft 6 extending rearwardly to a pump case 7 which incloses the adjacent ends of the rear axle sect-ions 8 The body-supporting frame of the chassis may be mounted in the usual manner upon suitable supporting springs not shown but ordinarily carried by the front and rear axles while the front wheels may also be connected to the front axle in such manner as to per- 9U mit steering of the machine by any suitable steering mechanism not necessary to herein illustrate or describe.

The outer ends of the axle sections 8- just inside of the wheels are journaled in suitable rotor casings 9- which in turn may be operatively connected to the supporting springs for the chassis frame in any suitable manner to hold them against rotation.

The pump case -7- is provided with a chamber -10- for receiving a rotary spider l1 which is keyed or otherwise secured to the rear end of the drive shaft -6- to be actuated thereby and is provided with a plurality of, in this instance six, radial cylinders 12- containing a 'corresponding number of pistons -13- reciprocally movable radially therein.

The periphery of the spider1l is circular and concentric with the axis of the drive shaft -6- while the major portion of the chamber l0 is also cylindrical and concentric with the axis of the spider -11- but is of slightly greater diameter than the spider except the diametri-cally opposite sides.

The casing -7- is provided with inwardly projecting ribs 1%- having curved inner faces concentric with said axis and in close proximity to the periphery of the spider -l1 to form substantially liquid-tight joints with said periphery without interfering with the free rotation of the spider.

The object of these ribs is to cut off direct communication between the lower and upper sides of the chamber -l0- and thereby to prevent the direct passage of the fluid from one side to the other, as will be hereinafter more fully described.

The rear end of the pump case 7 is provided with a forwardly projecting cylindrical hub 15- eccentric to the shaft -6 and in which the rear end of the shaft is journaled.

A sleeve -16- is journaled upon the periphery of the hub 15- for rotary or angular adjustment about the axis of said hu lThe distances between the axis of the relatively stationary hub -l5 and the axes of the sleeve -l6- and drive shaft -G are substantially equal so that when the sleeve -16- is adjusted angularly about the axis of the hub -l5--, its axis may be shifted into and out of registration or coincidence with that of the drive shaft for varying the stroke of the pistons -13- in a manner presently described.

The front end of the sleeve 16- is provided with a circular bearing concentric with the axis of said sleeve and upon this circular bearing is mounted a ring -17- having a plurality of radial arms l8- and -l8-, one for each piston, one of said radial arms as 18 being rigidly connected to the ring and constituting a pitman having its outer end pivotally connected to the corresponding piston -13-.

The remaining arms -1S-- are connected by pitmen -19- to their respective pistons and together with the rigid pitman -18- constitute the means for imparting reciprocatory movement to said pistons as the cylinders with the pistons therein together with the ring -17- are rotated upon the eccentric sleeve -16- by the rotation of the drive shaft -6-.

Any suitable means may be provided for effecting the angular adjustment of the sleeve -16- to vary the stroke of the pistons and for this purpose, the rear end of said sleeve is provided with a worm gear segment -20- concentric with its axis and engaged by a rotary worm 2lon a laterally extending tangential shaft -2.

This shaft is extended laterally through a tangential opening *Q3- in one side of the pump case -7 and is journaled in a suitable gland *24.- in the outer end of said opening, the outer end of the shaft being connected by bevel gears Q5- to a forwardly extending operating shaft -2G- as shown more clearly in Figures l and 3.

rhe forward end of the shaft *26m for adjusting the eccentric -16- may be provided with suitable means not shown within easy reaching distance of the driver by which it may be turned to effect the desired stroke or neutral position of the pistons while the machine is in operation.

The bearing -16- for the pitman ring -17- is eccentric to the axis of the stationary bearing l5- while the axis of the shaft -6- is disposed in the are of movement of the axis of the bearing -1G- which permits the axis of said bearing member -16- to be adjusted into and out of coincidence with that of the shaft as and for the purpose previously explained.

That is, when these axes are coincident, the pitman ring 17- will merely revolve around the axis of the shaft without imparting any reciprocatory movement to the pistons and thereby preventing the circulation of the impelling fluid through the rotors.

On the other hand, by shifting the eccentric 16- to bring its axis to either side of the axis of the shaft -6- will cause more or less reciprocatory movement of said pistons according to the angle of adjustment.

The opposite ends of the upper half of the chamber -10- are connected by oppositely extending pipes -27 to the upper halves of the corresponding rotor cases -9- while the opposite ends of the lower half of the chamber 10 are connected by oppositely extending pipes -27- to the lower halves of the corresponding rotor casings -9- as shown more clearly in Figure 5 except that one of the rotor casings is omitted.

The inner ends of the pipes -27- and -27- are tightly and permanently secured in suitable openings in opposite ends of the pump case --7- to form liquid and air-tight joints therewith while their outer ends are similarly secured in vertically spaced openings -28- in the inner ends of the rotor casings --9- to form liquid and air-tight joints.

The pump case -7 and parts mounted therein constitute what may be termed a combined dierential, speed changing and forward and reverse power transmitting mechanism, the pump case -7-, pipes -27- and -27 and rotor cases -9- forming the rear stationary axle and also a part of the circulatory system for the oil or other propelling fluid.

The rotor casings -9- are provided with enlarged annular chambers -29- for receiving suitable liquid impelled rotors 30- which are preferably cup-shaped and arranged with their open sides facing the openings -28- and are provided with internal gear teeth -8l constituting the wings or veins for receiving the impact of the circulating fluid.

These internal teeth are arranged in un1- formly spaced relation in the form of a gear and mesh with the teeth of suitable pinions -32- which in turn are journaled on studs -33- on the casing -9- as shown in Figures 4 and 6.

The traction wheels -3- may be of any desired construction and removably, but rigidly secured to the outer ends of a. pair of rotary axle sections S4-- which are centrally journaled in suitable bearings -35- in the inner and outer walls of the adjacent rotor casings -9 as shown in Figures 4 and 5, and also extend centrally through and are keyed or otherwise secured to and within the center hub of the corresponding rotors -30-, whereby the rotation of said rotors in either direction will impart similar rotary movement to the axle sections Seland their respective wheels -3- for propelling the machine either forwardly or backwardly according to the direction of rotation of the rotors.

The inner walls of the rotor chambers -29- are provided with radially extending partitions 36 -between the openings -28- and separating the corresponding pairs of openings one from the other, said partitions being extended around the hubs of their respective rotors -30- into close proximity to the inner faces of the outer end walls thereof to form liquid-tight joints therewith and also serve to receive and support the inner bea-rings for the axle sections -34.--.

These partitions -36- extend forwardly into close proximity to the inner faces of the gear teeth -31- to form liquid-tight joints therewith, without interfering with the free rotation of the rotors which are provided with circular peripheries running in close proximity to the peripheral walls of the casings -9- to forni liquid-tight joints therewith.

The pinions B2- are preferably located between the rear ends of their corresponding partitions -36- and the adjacent sides of the rotors -30- and travel in close proximity to the rear ends of said partitions to form liquid-tight joints therewith.

It is now evident that if the rotor impelling fluid is circulated through the passages provided therefor by the action of the pistons -13- whereby said fluid will be placed under pressure at one side of the partition -36- and pinions 3Q-1 and withdrawn from the opposite sides of said partitions and pinions, the rotors will be rotated in one direction toward the side of low-est pressure by pressure of the fluid on the high pressure side of the intermeshing teeth of the gears and pinions.

For example, assuming that the engine shaft -6-- and pump cylinder are driven in a counter clockwise direction Figure 5 and that the eccentric sleeve -16- is adjusted to bring its axis at the left hand side of the axis of said shaft, as shown in Figure 5, then the left hand piston 13- will be at the extreme limit of its outward movement in alinement with the adjacent partition -llwhile the right hand piston will be at the extreme limit of its inward stroke and the outer end of its cylinder will be covered by the adjacent partition lllunder which conditions, the pistons above the shaft -6- will be moving outwardly from the axis of said shaft while the pistons below the shaft will be moving inwardly.

This outward movement of the uppermost pistons will operate to force the oil or other impelling fluid from the upper side of the pump chamber l0 through the corresponding 10U passages Q7- and -28- into the upper portion of the rotors -30- for rotating said rotors in the direction indicated by arrow -m-, Figure 6, and thence returning from the lower half of the rotors through the corresponding passages -28 and --27 into the chambers of the receding pistons so that as soon as the several pistons register with the left hand partition -1l, Figure 5 and pass beyond said partition, the oil contained l in their respective cylinders will be again expelled by the outward movement of the pistons, thus completing one cycle of operation which is repeated for continuously rotating the rotors -30- and axle sections -34- 115 together with -the traction wheels -3- in the same direction for propelling the machine forwardly.

Now, if the eccentric sleeve -16- is adjusted to bring its axis into registration with that of the driving shaft --6-, it is evident that there will be no reciprocatory motion of the pistons and consequently no forcible circulation of the impelling fluid to the rotors through the passages previously described.

On the other hand, if the eccentric sleeve -16- is adjusted rotarily to bring its axis at the right hand of the axis of the driving shaft -6- while the pump cylinder 11 is rotated in the same direction or counter- Zit clockwise, Figure 5 the direction of flow of the impelling fluid through the circulating system to the rotors and return to the pump Will be reversed thereby reversing the direction of movement of the traction Wheels and machine propelled thereby.

lt is also evident from the foregoing description that the force of circulation of the impelling fluid is dependent upon the length of stroke of the pistons and that this stroke may be varied from zero to maximum as determined by the adjustment of the eccentric sleeve 1G thereby regulating the speed ol rotation of the rotors and traction Wheels propelled, thereby, and at the same time permitting differentiation of the speed of rotation of said rotors as for example, in turning corners Without interrupting` the circulation of the fluid.

These operations are true for either tor- Ward or reverse drive, the degree ot speed and direction ot motion of the machine being controlled entirely by the adjustment oi:l the cccentric member l6 'which in turn may be controlled by a single controlling member connected to the shaft 26- and placed Within convenient reaching distance of the driver of the machine.

Suitable means is provided i'or permitting local circulation of the impelling .fluid from one side to the other of the pump chamber to prevent excessive pressure ot the fluid in the circulating system in case the eccentric sleeve l6 should be suddenly shifted from either extreme position to a neutral position While the machine is moving under its own momentum and 'for this purpose is provided a bypass conduit flO Figures 2, 3 and T having its opposite ends connected to the lower and upper halt` of the pump chamber lO Figure 5, and its intermediate portion provided with a valve case M in which is mounted, a rotary and axially movable valve l2 This valve normally closes the passage through the conduit 40 but is provided With a diametrical opening therethrough adapted to be moved into registration With the passage in the conduit for permitting the local circulation of the impelling tluid therethrough trom one side to the other side of the chamber l0 in case the eccentric member 16 should be suddenly moved to a neutral position While the machine is in motion.

This valve may be adjusted at Will or through the medium oi any suitable connections with the shifting means for the eccentric sleeve 1G and for this purpose is mounted on a shaft M extending through one end ot the valve case M and provided at its Outer end with an operating member Figure 7.

Or, the valve may be mounted to operate automatically and tor this purpose, is movaipv/aser ble endwise in its chamber against the action ot opposed coil springs et6 Which yieldingly hold it in registration with the passage through the pipe M but permits it to be moved endivise to open said passage.

In order to permit this automatic operation, one end ot the valve chamber is connected by a branch passage str/ to the main passage in the pipe 4;0 at one side ot the valve While the other end of the chamber is connected by a branch passage 47 to the main passage at the opposite side of the valve as shown in Figure 7, so that the fluid under excess pressure at one side of the valve will pass through the adjacent branch passage M and 1i7 into the corresponding end oit the valve chamber and Will therefore torce the valve endwise to open the main passage and permit the circulation of the l'luid therethrough.

rhe pump cylinder l1 is fitted to revolve :treely in the pump case 7 and to iorm liquid-tight oints therewith which may be increased by the use of Suitable packing rings i9 ligure 2, in which it Will be observed, the end walls ot' the pump case are removable but are normally clamped tightly in place by suitable bolts 50 thus permitting access to the interior mechanism for repairs or replacements When desired.

in a similar manner, one end Wall of each of the rotor casings Q is removable, but is normally held in place by bolts 5l Figure 5.

l claim:

l. ,ln hydraulic transmission for motor vehicles, an axle frame comprising a pump case having each ot' its opposite ends provided with a pair of ports, tubes secured to and eX- tending laterally in opposite directions from said ports, rotor casings arranged in spaced relation to and at opposite ends of the pump case and each provided with a pair of ports in which the adjacent ends oi the corresponding tubes are secured, Wheel-supporting axles journaled in said rotor casings, engine-driven means Within the pump case for circulating a luid through said ports and tubes, and rotors secured to said axles ,.vithin their respective rotor casings and actuated by the circulation olf fluid through the ports of said casings, said pump ease and the rotor casings being arranged in the vertical plane of the axis oi the Wheel-supporting axle.

2. ln hydraulic poiver transmission for motor vehicles, an axle trame comprising a pump case having a pair of ports leading from opposite ends of its pressure side and an additional pair ot ports leading from opposite ends ot its suction side, a pair of tubes secured to and leadincin opposite directions 'from the pressure ports, an additional pair of tubes secured to and leading in opposite directions from the suction ports, rotor casings at opposite ends of the pump case in spaced relation and each provided with a pressure port and a suction port connected respectively to the adjacent ends or" the corresponding pressure tube and suction tube, a motordriven rotary pump within the pump case for circulating a liquid through the pressure tubes and rotor cases and return through the suction tubes, and rotors in said casings actuated by the circulation of the liquid, said pump case and the rotor casings being arranged in the vertical plane of the axis of said rotors and the respective pairs of tubes being disposed at equal distances either side of said axis.

3. In hydraulic transmission for motor vehicles, an axle Jframe comprising a pump case, rotor casings at opposite ends of the pump case in spaced relation thereto, upper and lower sets of tubes connecting the pump case and rotor casings, wheel-supporting axles journaled in the outer ends of the rotor casings, a motor-driven pump within the pump case for circulating a liquid through one set of tubes to the rotor casings and return through the other set of tubes to the pump case, and rotors within said casings actuated by the circulation of the liquid, said pump case and the rotor casings being arranged in the vertical plane of the axis of said wheel-supporting axles and the respective tubes of each set being spaced equal distances either side of said axis.

4. Hydraulic transmission as in claim 3 including a by-pass connecting the pressure and suction sides of the pump, a rotary piston valve having an opening therethrough and yieldingly held against axial movement, means for rotating the valve to bring the opening into and out of registration with the by-pass for opening and closing said by-pass and branch passages leading from the by-pass at opposite sides of the valve to the valve chamber at opposite ends of the valve for opening said valve in case of excess liquid pressure at either side of the valve.

5. In hydraulic transmission for motor vehicles having opposite coaxial driving wheels, an axle frame comprising a pump case midway between the wheels and having a circular pump-chamber divided into lower and upper compartments, rotor-casings adjacent the driving wheels and provided with journal bearings therefor, said casings having circular rotor-chambers divided into lower and upper compartments, pipes connecting the lower compartments of the pump case and r0- tor casings, additional pipes connecting the upper compartments of said case and casings, a motor-driven pump in the pump case for circulating a liquid through one set of pipes and return through the other set of pipes, and r0- tor in the rotor-casings actuated by the circulation of the liquid through the compartments of the casings and operatively connected to the driving wheels for rotating the same, 

